BDNF down-regulates the caspase 3 pathway in injured geniculo-cortical neurones.

Visual cortex ablation in newborn rats causes a rapid and almost complete degeneration of neurones in the dorsal lateral geniculate nucleus (dLGN), as a consequence of the axotomy of geniculocortical fibres. Death of dLGN neurones occurs by apoptosis and is partially prevented (similar to50%) by intraocular delivery of brain-derived neurotrophic factor (BDNF). Here we investigated the molecular mechanisms of BDNF-mediated neuroprotection. We found that exogenous administration of BDNF partially decreases (similar to50%) the up-regulation of apoptotic proteins (phosphorylated c-Jun, cytochrome C and cleaved caspase 3), that occurs in dLGN neurones following visual cortex ablation at postnatal day 7 These results demonstrate that the neuroprotective action of BDNF on axotomised dLGN neurones involves the partial blockade of well-characterised apoptotic pathways.